Research has revealed that contracting viral infections such as influenza and Covid-19 significantly heightens the risk of severe cardiovascular events, including heart attacks and strokes. A comprehensive analysis of 155 studies published by the American Heart Association indicates that these infections can increase the likelihood of such complications by three to five times in the weeks following the infection.
The study, led by Associate Professor Kosuke Kawai from the University of California, highlights the urgent need for vaccination as a potential preventative measure, particularly for individuals with pre-existing cardiovascular risk factors. Kawai noted, “It is well recognised that human papillomavirus (HPV), hepatitis B virus and other viruses can cause cancer; however, the link between viral infections and other non-communicable diseases, such as cardiovascular disease, is less well understood.”
The researchers aimed to thoroughly examine the connections between viral infections and cardiovascular disease, scrutinizing an initial pool of 52,000 studies before narrowing it down to 155 based on design and quality. The findings were striking: the risk of experiencing a heart attack was found to be four times greater, while the probability of suffering a stroke increased fivefold within one month of a confirmed influenza infection.
In the case of Covid-19, individuals were found to be three times more likely to have a heart attack and experience a stroke within 14 weeks following infection, with heightened risks persisting for up to a year. The study also indicated that individuals living with HIV face a 60% higher risk of heart attacks and a 45% increased risk of strokes over an average follow-up period of more than five years. Similar elevated risks were noted among those with hepatitis C and varicella zoster virus, commonly known as shingles.
Kawai elaborated, “The elevated risks for cardiovascular disease are lower for HIV, hepatitis C, and herpes zoster than the heightened short-term risk following influenza and Covid-19. However, the risks associated with those three viruses are still clinically relevant, especially because they persist for a long period of time.” He added that shingles affects about one in three people in their lifetime, translating into a significant public health concern.
Despite the importance of these findings, the research team acknowledged limitations, particularly their reliance on observational data rather than controlled trials. Nonetheless, they advocate for vaccination as a critical component of reducing cardiovascular risks. In the UK, for example, the NHS offers flu vaccinations each autumn and early winter to those at higher risk of serious complications.
Starting from September 1, 2023, six groups became eligible to receive flu vaccinations, including secondary school-aged children and pregnant women. An additional six categories, encompassing care home residents and frontline health workers, were eligible from October 1, 2023.
Furthermore, specific groups are advised to receive a winter Covid-19 jab, including residents of care homes for older adults and individuals aged 75 or over. Those with weakened immune systems due to health conditions are also encouraged to get vaccinated.
For detailed information on vaccination eligibility and availability, the NHS provides resources on its official website. As the evidence mounts regarding the relationship between viral infections and cardiovascular health, public health initiatives will be essential in mitigating these risks and protecting vulnerable populations.
